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排序方式: 共有1143条查询结果,搜索用时 359 毫秒
111.
Tarek O. Al Kasabi Said I. Abdel-Khalik Terry E. Dix Randy Hagenson Abdo A. Husseiny Gary P. Mclagan 《Desalination》1981
A completely solar-powered greenhouse complex has been designed for climate controlled food production in hot, humid environments. The concept uses passive design features to provide irrigation water from saline water sources. This paper discusses the overall system concept and the solar still subsystem which has been designed to provide a continuous fresh water supply. While incorporating many innovative features, the use of proven technologies and passive design results in a system that should compete economically with current, more traditional designs. 相似文献
112.
Said Jahanmir 《Wear》1981,73(1):169-183
Examination of steel specimens tested under boundary lubrication conditions indicates the existence of three distinct processes which lead to wear particle formation: deformation and fracture of original machining marks; deformation and fracture of edges of plowing tracks; delamination. Deformation and fracture of original machining marks and the raised edges of the plowing furrows generate wear particles which are 1–15 μm in the largest dimension. The process of delamination, however, generates particles that are 100 μm wide. The formation of these large wear particles coincides with a high rate of wear and scuffing failure. 相似文献
113.
A. A. Said 《Journal of Materials Science》1992,27(21):5869-5872
The thermal decomposition of ammonium metavanadate (AMV) supported on aluminium oxide was investigated using differential thermal analysis, thermogravimetry, infrared and X-ray diffraction techniques. The results obtained revealed that the decomposition of AMV supported on alumina proceeded in three decomposition stages. Alumina was found to enhance only the decomposition of the intermediate ammonium hexavanadate to produce V2O5. In addition, the values of activation energies of the various decomposition stages were accompanied by a significant decrease on decreasing the concentration of AMV. The infrared spectra indicated that the band corresponds to the surface site V=O strongly affected by the presence of Al2O3. Finally, an interaction between Al2O3 and V2O5 occurred at 660 °C giving well-crystallized AlVO4. 相似文献
114.
Said S. Ibrahim Ferial M. Abu Salem M. A. Abdallah 《Molecular nutrition & food research》1975,19(3):207-211
In this study processed mango juice was packed in four types of containers and stored at different temperatures for 16 weeks through which furfural level determination and organoleptic assessment were conducted. The experiment revealed an evident relationship to exist among furfural level, storage temperature and type of packing material. Furfural level failed to closely parallel flavour difference; therefore it could be regarded as one of the features concomitant juice aging rather than accepted as a satisfactory criterion of off flavour. The study relates flavour deterioration to the changes in the lipid fraction of the juice. 相似文献
115.
Said A. Khalil Lobna M. Mortada Fatma A. Ismail 《Drug development and industrial pharmacy》1984,10(6):929-948
An in vivo absorption study was performed in a crossover fashion on 6 healthy volunteers (4 males and 2 females) to compare the bioavailability of 8 brands of ampicillin capsules. Absorption was assessed by a urinary excretion method in which the drug was assayed chemically. Statistical analysis of the results was carried out to evaluate the significance of differences between brands and between subjects. Results of the analysis of variance indicated no significant differences between the tested brands of ampicillin capsules. However, significant differences between brand A and brand B were found on using the student t-test. A significant intersubject variation was also found between the volunteers participated in the present study. 相似文献
116.
Said M. A. Ibrahim 《Energy》1984,9(11-12)
We present a thermodynamic comparison of combustion processes for the production of high-temperature gases (2000–3100 °K) from methane. We compare:
- 1. (1) CH4---O2 mixtures, with oxygen added either in the gaseous or the liquid state,
- 2. (2) CH4-enriched air systems, with enrichment by removal of gaseous nitrogen from air,
- 3. (3) CH4-enriched air systems, with enrichment achieved by adding either pure gaseous or pure liquid oxygen to air, and
- 4. (4) CH4-air electrically augmented systems, in which enriched air is produced in an air-separation plant and electrical augmentation is produced by applying strong electric fields between electrodes immersed in the flame gases.
117.
The protein value of meat soy blend was evaluated by utilizing the net protein ratio (NPR), the relative protein value (RPV) and the serum urea content methods. It was compared with that of meat. Casein was used as a reference protein. NPR values indicated that utilization of meat and meat soy proteins are comparable. The study of amino acid pattern shows that sulphur containing amino acids are limiting to almost the same degree in meat and meat soy blend. However, the RPV of meat soy bean blend is slightly higher than that of meat. The lowest serum urea content was that of rats fed meat soy blend. Therefore, the mixing of meat with soy bean did not reduce the nutritive value of meat, on the contrary there is tendency towards improvement. 相似文献
118.
MA Lones D Lopez-Terrada IP Shintaku J Rosenthal JW Said 《Canadian Metallurgical Quarterly》1998,122(8):708-714
Two new antibiotics, hongoquercins A and B, were isolated from fermentation extracts of the unidentified fungus LL-23G227. In the optimum medium, titers of the A and B components reached approximately 2.1 g/liter and 0.02 g/liter, respectively. The optimum temperature for antibiotic production was approximately 22 degrees C. Growth was delayed at 15 degrees C but appeared to reach higher levels than was observed at 22 degrees C. Addition of dextrose to growth media increased hongoquercin B production. Hongoquercin A exhibited moderate activity against Gram-positive bacteria. Mechanistic studies conducted in an E. coli imp strain suggested membrane damage as the primary mode of bactericidal action. These compounds also lysed human red blood cells, suggesting a similar mode of action on eukaryotic cells. 相似文献
119.
120.
Stochastic Priority Model for Aggregate Blending 总被引:1,自引:0,他引:1
Aggregate blending models that incorporate the optimization of two objectives with their priority levels are presented. The two objectives include the minimization of the mean deviation (or mean absolute deviation) from the midpoint of specification limits and the minimization of the unit cost of the blend. The models are applicable to any number of aggregates and can be used to provide the optimum proportions corresponding to a given priority level or to establish trade‐off curves between mean deviation and cost. The stochastic elements of aggregate gradations are formulated and incorporated into the models. Both the deterministic and stochastic models are applied to a numerical aggregate blending problem, and extensions of the models to accommodate some practical cases are presented. 相似文献